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P1573

PCM/EBTCM Serial Data Circuit.

  • Buick
  • Powertrain
  • Manufacturer code
  • Medium severity

How this code is built

P
SystemPowertrain
1
Defined byThe manufacturer
5
AreaVehicle speed, idle control and auxiliary inputs
73
FaultThe specific fault in that area

What it means

On a Buick, P1573 means the powertrain control module (PCM) has lost or received invalid serial data communication with the electronic brake and traction control module (EBTCM). The PCM expects regular messages from the EBTCM on the data link and sets the code when they are missing or corrupted. The exact circuit layout and the conditions for setting the code vary by model and year.

Symptoms

  • ABS and/or traction control warning light on
  • Check engine light or service engine soon light on
  • Traction control disabled or behaving erratically
  • Possible reduced engine power or limited torque management
  • Intermittent speedometer or wheel speed related faults
  • Other scan tool communication problems with the brake module

Possible causes

  • Damaged, chafed or corroded wiring in the serial data circuit between the PCM and EBTCMlikely
  • Loose, corroded or spread terminals at the PCM or EBTCM connectorslikely
  • Low battery voltage or poor power and earth supply to the EBTCMpossible
  • Faulty EBTCM (internal communication fault)possible
  • Faulty PCM or outdated PCM softwarerare
  • Water ingress or previous repair damage affecting harness or connectorspossible

How to diagnose

  1. Read all stored codes and freeze frame data, noting any brake module or wheel speed codes stored alongside P1573, and whether the code is current or history.
  2. Check battery condition and charging voltage, as low voltage can cause communication faults.
  3. Check the relevant fuses and the power and earth supplies to the EBTCM.
  4. Visually inspect the harness and connectors between the PCM and EBTCM for chafing, corrosion, water or previous repair damage.
  5. Check that the EBTCM responds to a scan tool; if it does not, suspect the module's supply or the data circuit.
  6. Test the serial data circuit for continuity, short to earth and short to voltage using the manufacturer wiring diagram for the specific model.
  7. Wiggle test the harness and connectors with the scan tool monitoring to find intermittent faults.
  8. Check for a service bulletin or software update relevant to the model and year before condemning a module.

How to fix

  • Repair or replace damaged wiring in the serial data circuit.
  • Clean, repair or replace corroded or loose connector terminals.
  • Restore correct power and earth supply to the EBTCM, and charge or replace a weak battery.
  • Replace or repair the EBTCM if confirmed faulty, then perform any required setup procedure.
  • Update the PCM calibration if an outdated one is a known cause for that model, or replace the PCM if confirmed faulty.

Can I keep driving?

Medium severity

The car is usually driveable, but ABS and traction control may be reduced or unavailable, so drive with extra care and book it in soon. Stop driving if the brakes feel abnormal or other brake warnings appear.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.

This code for other makes

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